Multilayer golf ball

ABSTRACT

The present invention encompasses a golf ball having a diameter and being comprised of a core and a cover, wherein the core is further comprised of a fluid mass at the center of the ball, and a first, solid, non-wound mantle layer surrounding the fluid mass, wherein the first mantle layer comprises a copolymer or terpolymer of ethylene and an α,β-unsaturated carboxylic acid, the acid being neutralized at least 80% by a salt of an organic acid, a cation source, or a suitable base of the organic acid, and wherein the cover comprises polyurethane, polyurea, or a polyurea/polyurethane hybrid. Preferably, the rate of spin decay is at least 10% of an initial spin rate of the golf ball over the entire ball flight.

This application is a continuation of co-pending U.S. patent applicationSer. No. 12/275,615, filed Nov. 21, 2008, which is a continuation ofU.S. patent application Ser. No. 11/353,563, filed Feb. 14, 2006, nowU.S. Pat. No. 7,458,904, which is a continuation-in-part of U.S. Pat.No. 7,041,007, filed on Sep. 26, 2003, which is a continuation-in-partof U.S. Pat. No. 6,635,133, which is a divisional of U.S. Pat. No.6,575,846, which is a continuation of U.S. patent application Ser. No.08/902,351, filed on Jul. 29, 1997, now abandoned, which is acontinuation-in-part of U.S. Pat. No. 5,683,312. These applications arehereby incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The present invention is directed to a multilayered golf ball having aplurality of core parts arranged around a center and bound to each otherby an adhesive. Particularly, the present invention encompasses a golfball having a core comprised of a fluid mass at the center of the ball,and a non-wound first mantle layer surrounding the fluid mass.

BACKGROUND OF THE INVENTION

Generally, golf balls have been classified as two piece balls or threepiece balls. Two piece balls are comprised of a solid polymeric core anda cover. These balls are generally easy to manufacture, but are regardedas having limited playing characteristics. Three piece balls arecomprised of a solid or liquid-filled center surrounded by tensionedelastomeric material and a cover. Three piece balls generally have agood “click” and “feel” when struck by a golf club, but are moredifficult to manufacture than two piece balls.

The prior art is comprised of various golf balls that have been designedto provide optimal playing characteristics. These characteristics aregenerally the initial velocity and spin of the golf ball, which can beoptimized for various players. For instance, certain players prefer toplay a ball that has a high spin rate for playability. Other playersprefer to play a ball that has a low spin rate to maximize distance.However, these balls tend to be hard feeling and difficult to controlaround the greens.

The prior art is comprised of liquid filled golf balls. Wound golf ballshave been made with liquid filled centers for many years. Both U.S. Pat.Nos. 1,568,513 and 1,904,012 are directed to wound golf balls withliquid filled centers. U.S. Pat. Nos. 5,150,906 and 5,480,155, aredirected to a hollow spherical shell of a polymeric material which isfilled with a liquid or unitary, non-cellular material that is a liquidwhen introduced into the shell. The shell is disclosed as being theouter cover or an inner layer with the outer cover formed to theexternal surface thereof. The shell varies in thickness from about 0.060to 0.410 inches in thickness.

Other known attempts to mold layers around a solid center entail placinga preformed center between two blocks of core material in a sphericalcompression mold, and closing the mold. This is done in the manufactureof golf balls sold by Kamatari. This process, however, provides littlecontrol over the ultimate placement of the center within the golf ballcore. Large variations in center eccentricities can result.

The prior art also provides for the manufacture of double cover golfballs. This is generally accomplished by injection molding a first andthen a second cover layer around a core. This system, however, requirescomplex injection molds, usually with retractable pins within the moldto properly position the core.

SUMMARY OF THE INVENTION

The present invention relates to a golf ball having a diameter and beingcomprised of a core and a cover, wherein the core is further comprisedof a fluid mass at the center of the ball, a first mantle layersurrounding the fluid mass and a second, solid, non-wound mantle layersurrounding and abutting the first mantle layer, wherein the firstmantle layer comprises a polymer material selected from the groupconsisting of a thermoset rubber, plastic and thermoplastic elastomericmaterial and the second mantle layer comprises a polymer materialselected from the group consisting of a thermoset rubber material andthermoplastic elastomeric material, and wherein the cover comprisespolyurethane, polyurea, or a polyurea/polyurethane hybrid.

In one embodiment, the fluid mass in the core is a gas, liquid, gel,paste or a combination thereof. In another embodiment, the fluid mass isa liquid having a low coefficient of thermal expansion or high boilingpoint. In a preferred embodiment, the fluid mass is a liquid having alow coefficient of thermal expansion or high boiling point that isselected from the group consisting of an oil, a polyol and mixturesthereof. In yet another embodiment, the fluid mass is a gas, wherein thegas is selected from the group consisting of air, nitrogen, helium,argon, neon, carbon dioxide, nitrous oxide and mixtures thereof.

In one embodiment, the first mantle layer comprises dynamicallyvulcanized thermoplastic elastomer, functionalized styrene-butadieneelastomer, thermoplastic polyurethane, thermoplastic polyetherester orpolyetheramide, thermoplastic ionomer resin, thermoplastic polyester,metallocene polymer or blends thereof. In another embodiment, the covercomprises an inner cover layer and a thin outer cover layer, wherein theouter cover layer comprises a thermoset material formed from a castable,reactive liquid and the inner cover layer comprises a high flexuralmodulus material.

In yet another embodiment, the core, cover, first mantle layer or secondmantle layer comprises a polymer containing an acid group that isneutralized by an organic acid or a salt thereof, the organic acid orsalt thereof being present in an amount sufficient to neutralize thepolymer by at least about 70%. In a preferred embodiment, the polymercomprises ionomeric copolymers and terpolymers, ionomer precursors,thermoplastics, thermoplastic elastomers, polybutadiene rubber, balata,grafted metallocene-catalyzed polymers, non-graftedmetallocene-catalyzed polymers, single-site polymers, high-crystallineacid polymers, cationic ionomers, and mixtures thereof. In anotherpreferred embodiment, the organic acid is selected from the groupconsisting of aliphatic organic acids, aromatic organic acids, saturatedmono-functional organic acids, unsaturated mono-functional organicacids, and multi-unsaturated mono-functional organic acids. In yetanother preferred embodiment, the salt of organic acids comprise barium,lithium, sodium, zinc, bismuth, chromium, cobalt, copper, potassium,strontium, titanium, tungsten, magnesium, cesium, iron, nickel, silver,aluminum, tin, and calcium salts of stearic acid, behenic acid, erucicacid, oleic acid, linoelic acid, dimerized derivatives, and mixturesthereof.

In one embodiment, the golf ball diameter is at least 1.68 inches. Inanother embodiment, the first mantle layer has an inner diameter ofabout 0.75 to 1.1 inches. In yet another embodiment, the core diameteris about 1.590 inches or greater. In another embodiment, the cover has athickness of from about 0.015 to 0.12 inches.

In another embodiment, the first mantle layer or second mantle layerfurther comprises a halogenated thiophenol. Preferably, the halogenatedthiophenol is zinc pentachlorothiophenol.

In yet another embodiment, the cover comprises polyether polyesterthermoplastic urethane, thermoset polyurethane, polyurea, orpolyurethane/polyurea hybrid that is formed from an isocyanateprepolymer. Preferably, the isocyanate prepolymer is paraphenylenediisocyanate.

In one embodiment, the golf ball has a moment of inertia of greater than0.460 oz-in². In another embodiment, the golf ball has a moment ofinertia of less than 0.450 oz-in².

The present invention also encompasses a golf ball having a diameter andbeing comprised of a core and a cover, wherein the core is furthercomprised of a fluid mass at the center of the ball, a first mantlelayer surrounding the fluid mass and a second, solid, non-wound mantlelayer surrounding and abutting the first mantle layer, wherein the firstmantle layer comprises a polymer material selected from the groupconsisting of a thermoset rubber, plastic and thermoplastic elastomericmaterial and the second mantle layer comprises a polymer materialselected from the group consisting of a thermoset rubber material andthermoplastic elastomeric material, and wherein the cover comprisesmaterial selected from the group consisting of polyether and polyesterthermoplastic urethane, thermoset polyurethane, ionomer resins, lowmodulus ionomers, high modulus ionomers and blends thereof. In oneembodiment, the cover comprises a thermoset polyurethane.

In one embodiment, the fluid mass a liquid having a low coefficient ofthermal expansion or high boiling point. In a preferred embodiment, thefluid mass is a liquid having a low coefficient of thermal expansion orhigh boiling point that is selected from the group consisting of an oil,a polyol and mixtures thereof. In yet another embodiment, the fluid massis a gas, wherein the gas is selected from the group consisting of air,nitrogen, helium, argon, neon, carbon dioxide, nitrous oxide andmixtures thereof.

In one embodiment, the first mantle layer comprises dynamicallyvulcanized thermoplastic elastomer, functionalized styrene-butadieneelastomer, thermoplastic polyurethane, thermoplastic polyetherester orpolyetheramide, thermoplastic ionomer resin, thermoplastic polyester,metallocene polymer or blends thereof. In another embodiment, the covercomprises an inner cover layer and a thin outer cover layer, wherein theouter cover layer comprises a thermoset material formed from a castable,reactive liquid and the inner cover layer comprises a high flexuralmodulus material.

In yet another embodiment, the core, cover, first mantle layer or secondmantle layer comprises a polymer containing an acid group that isneutralized by an organic acid or a salt thereof, the organic acid orsalt thereof being present in an amount sufficient to neutralize thepolymer by at least about 70%. In a preferred embodiment, the polymercomprises ionomeric copolymers and terpolymers, ionomer precursors,thermoplastics, thermoplastic elastomers, polybutadiene rubber, balata,grafted metallocene-catalyzed polymers, non-graftedmetallocene-catalyzed polymers, single-site polymers, high-crystallineacid polymers, cationic ionomers, and mixtures thereof. In anotherpreferred embodiment, the organic acid is selected from the groupconsisting of aliphatic organic acids, aromatic organic acids, saturatedmono-functional organic acids, unsaturated mono-functional organicacids, and multi-unsaturated mono-functional organic acids. In yetanother preferred embodiment, the salt of organic acids comprise barium,lithium, sodium, zinc, bismuth, chromium, cobalt, copper, potassium,strontium, titanium, tungsten, magnesium, cesium, iron, nickel, silver,aluminum, tin, and calcium salts of stearic acid, behenic acid, erucicacid, oleic acid, linoelic acid, dimerized derivatives, and mixturesthereof.

In one embodiment, the golf ball diameter is at least 1.68 inches. Inanother embodiment, the first mantle layer has an inner diameter ofabout 0.75 to 1.1 inches. In yet another embodiment, the core diameteris about 1.590 inches or greater. In another embodiment, the cover has athickness of from about 0.015 to 0.12 inches.

In another embodiment, the first mantle layer or second mantle layerfurther comprises a halogenated thiophenol. Preferably, the halogenatedthiophenol is zinc pentachlorothiophenol.

In one embodiment, the golf ball has a moment of inertia of greater than0.460 oz-in². In another embodiment, the golf ball has a moment ofinertia of less than 0.450 oz-in².

The present invention further encompasses a golf ball having a diameterand being comprised of a core and a cover, wherein the core is furthercomprised of a fluid mass at the center of the ball, a first mantlelayer surrounding the fluid mass and a second, solid, non-wound mantlelayer surrounding and abutting the first mantle layer, wherein the firstmantle layer comprises a polymer material selected from the groupconsisting of a thermoset rubber, plastic and thermoplastic elastomericmaterial and the second mantle layer comprises two or more layers, eachmade from material that comprises a polymer material selected from thegroup consisting of a thermoset rubber material and thermoplasticelastomeric material. In a preferred embodiment, the thermoset rubbermaterial is selected from the group consisting of polyisoprene, styrenebutadiene, polybutadiene and mixtures thereof. In another preferredembodiment, the thermoplastic elastomeric material is selected from thegroup consisting of copolymers of methyl-methacrylate with butadiene andstyrene, copolymers of methyl-acrylate with butadiene and styrene,acrylonitrile styrene copolymers, polyether-ester, polyether-amide,polyurethane, propylene/ethylene-propylene-diene rubber,styrene-butadiene elastomers, metallocene polymers, polyetheresters,polyetheramides, ionomer resins, polyesters, and blends thereof.

In one embodiment, the fluid mass in the core is a liquid having a lowcoefficient of thermal expansion or high boiling point. In a preferredembodiment, the fluid mass is a liquid having a low coefficient ofthermal expansion or high boiling point that is selected from the groupconsisting of an oil, a polyol and mixtures thereof. In yet anotherembodiment, the fluid mass is a gas, wherein the gas is selected fromthe group consisting of air, nitrogen, helium, argon, neon, carbondioxide, nitrous oxide and mixtures thereof.

In one embodiment, the first mantle layer comprises dynamicallyvulcanized thermoplastic elastomer, functionalized styrene-butadieneelastomer, thermoplastic polyurethane, thermoplastic polyetherester orpolyetheramide, thermoplastic ionomer resin, thermoplastic polyester,metallocene polymer or blends thereof. In another embodiment, the covercomprises an inner cover layer and a thin outer cover layer, wherein theouter cover layer comprises a thermoset material formed from a castable,reactive liquid and the inner cover layer comprises a high flexuralmodulus material.

In yet another embodiment, the core, cover, first mantle layer or secondmantle layer comprises a polymer containing an acid group that isneutralized by an organic acid or a salt thereof, the organic acid orsalt thereof being present in an amount sufficient to neutralize thepolymer by at least about 70%. In a preferred embodiment, the polymercomprises ionomeric copolymers and terpolymers, ionomer precursors,thermoplastics, thermoplastic elastomers, polybutadiene rubber, balata,grafted metallocene-catalyzed polymers, non-graftedmetallocene-catalyzed polymers, single-site polymers, high-crystallineacid polymers, cationic ionomers, and mixtures thereof. In anotherpreferred embodiment, the organic acid is selected from the groupconsisting of aliphatic organic acids, aromatic organic acids, saturatedmono-functional organic acids, unsaturated mono-functional organicacids, and multi-unsaturated mono-functional organic acids. In yetanother preferred embodiment, the salt of organic acids comprise barium,lithium, sodium, zinc, bismuth, chromium, cobalt, copper, potassium,strontium, titanium, tungsten, magnesium, cesium, iron, nickel, silver,aluminum, tin, and calcium salts of stearic acid, behenic acid, erucicacid, oleic acid, linoelic acid, dimerized derivatives, and mixturesthereof.

In one embodiment, the golf ball diameter is at least 1.68 inches. Inanother embodiment, the first mantle layer has an inner diameter ofabout 0.75 to 1.1 inches. In yet another embodiment, the core diameteris about 1.590 inches or greater. In another embodiment, the cover has athickness of from about 0.015 to 0.12 inches.

In another embodiment, the first mantle layer or second mantle layerfurther comprises a halogenated thiophenol. Preferably, the halogenatedthiophenol is zinc pentachlorothiophenol.

In one embodiment, the golf ball has a moment of inertia of greater than0.460 oz-in². In another embodiment, the golf ball has a moment ofinertia of less than 0.450 oz-in².

In another embodiment, a golf ball having a diameter and being comprisedof a core and a cover is provided. The core is further comprised of afluid mass at the center of the ball, and a first, solid, non-woundlayer surrounds the fluid mass. The first layer comprises a copolymer orterpolymer of ethylene and an α,β-unsaturated carboxylic acid, the acidbeing neutralized at least 80% by a salt of an organic acid, a cationsource, or a suitable base of the organic acid. The cover comprisespolyurethane, polyurea, or a polyurea/polyurethane hybrid.

According to another embodiment, a golf ball having a diameter and beingcomprised of a core and a cover is provided. The core is furthercomprised of a fluid mass at the center of the ball, a shellencompassing the fluid mass, and a first, solid, non-wound mantle layersurrounding the shell. The first mantle layer comprises a copolymer orterpolymer of ethylene and an α,β-unsaturated carboxylic acid, the acidbeing neutralized at least 80% by a salt of an organic acid, a cationsource, or a suitable base of the organic acid. The cover comprisespolyurethane, polyurea, or a polyurea/polyurethane hybrid.

In yet another embodiment, a golf ball having a diameter and beingcomprised of a core and a cover is provided. The core is comprised of afluid mass at the center of the ball, and a first, solid, non-woundmantle layer surrounding the fluid mass. The first mantle layercomprises a copolymer or terpolymer of ethylene and an α,β-unsaturatedcarboxylic acid, the acid being neutralized at least 80% by a salt of anorganic acid, a cation source, or a suitable base of the organic acid.The cover comprises polyurethane, polyurea, or a polyurea/polyurethanehybrid. The rate of spin decay for the golf ball is at least 10% of aninitial spin rate of the golf ball over the entire ball flight.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention can be ascertained fromthe following detailed description that is provided in connection withthe drawings described below:

FIG. 1 is a sectional view of a ball of the present invention;

FIG. 2 is a sectional view of a ball according to the present inventionwith the liquid center shell and multiple mantle and cover layers aroundan inner sphere;

FIG. 3 is a sectional view of a mold preforming a single cup;

FIG. 4 is a sectional view of molds preforming a mantle layer's cupsaccording to the present invention;

FIG. 5 is a sectional view of molds joining cups of a golf ball mantlelayer;

FIG. 6 is a sectional view of the mold joining cups of a golf ballmantle layer around an inner sphere of frozen fluid;

FIG. 7 is a sectional view of a ball according to the invention havingadhesive joining the cups;

FIG. 8 illustrates a compression mold forming a cover around a golf ballcore;

FIG. 9 shows an injection mold forming a cover around a core;

FIGS. 10 and 11 are sectional views of cups with nonplanar matingsurfaces that mesh with one another;

FIG. 12 is a sectional view of a ball according to another embodiment ofthe invention;

FIGS. 13A-13D are sectional views of the liquid centers of ballsaccording to embodiments of the invention having an inner surface thatis modified with an increased surface area; and

FIGS. 14A-D are graphs depicting spin decay rates for the presentinvention and prior art golf balls.

DETAILED DESCRIPTION OF THE INVENTION

The golf balls of the present invention encompass any type of ballconstruction. For example, the golf ball may have at least a three-piecedesign, a multi-layer core, a multi-layer cover, one or more mantle orintermediate layers. As used herein, the term “multi-layer” means atleast two layers. As used herein, the term “layer” includes anygenerally spherical portion of a golf ball, i.e., a golf ball core orcenter, mantle layer, and or a golf ball cover.

Referring to FIG. 1, ball 10 includes a cover 11 and a core 12. As usedherein, the term “core” means the innermost portion of a golf ball, andmay include one or more layers. When a multi-layer core is contemplated,the core is the innermost component with one or more additional corelayers disposed thereon. At least a portion of the core, typically thecenter, is solid, semi-solid, hollow, powder-filled or fluid-filled,preferably fluid-filled. As used herein, the term “fluid” means a gas,liquid, gel, paste, or the like, or a combination thereof. In oneembodiment, the core 12 has an inner sphere 13 that is disposedconcentrically therein and which preferably comprises a fluid center 18in a cavity within a liquid center shell 20.

In one embodiment, the core 12 also has a first mantle layer 22, whichsurrounds the inner sphere 13. Together, the liquid center shell 20 andthe first mantle layer 22 are part of a mantle portion 16 of the ball.The mantle portion 16 of FIG. 2 has an additional second mantle layer40. The liquid center shell 20 and mantle layers 22 and 40 arepreferably elastomers.

A “mantle layer” (also known as inner layer or intermediate layer) isdefined herein as a portion of the golf ball that occupies a volumebetween the cover and the core. Such a mantle layer may be distinguishedfrom a cover or a core by some difference between the golf ball layers,e.g., hardness, compression, thickness, and the like. A mantle layer maybe used, if desired, with a multilayer cover or a multilayer core, orwith both a multilayer cover and a multilayer core. Accordingly, amantle layer is also sometimes referred to in the art as an inner coverlayer, as an outer core layer or as an intermediate layer, i.e., anylayer(s) disposed between the inner core and the outer cover of a golfball, this layer may be incorporated, for example, with a single layeror a multilayer cover, with a one-piece core or a multilayer core, withboth a single layer cover and core, or with both a multilayer cover anda multilayer core. As with the core, the mantle layer may also include aplurality of layers. It will be appreciated that any number or type ofmantle layers may be used, as desired.

The cover 11 provides the interface between the ball 10 and a club andother objects such as trees, cart paths, and grass. Properties that aredesirable for the cover are good flowability, high abrasion resistance,high tear strength, high resilience, and good mold release, amongothers. The golf ball can comprise one cover layer, or two or more coverlayers, such as those disclosed in U.S. Pat. No. 5,885,172, the entiredisclosure of which is incorporated herein by reference. For example,golf balls having multilayer covers can comprise an inner cover layerand a thin outer cover layer, wherein the outer cover layer comprises athermoset material formed from a castable, reactive liquid and the innercover layer comprises a high flexural modulus material. Preferably, thecover 11 is comprised of one or more layers that are injection molded,compression molded, cast or reaction injection molded.

The cover 11 can be comprised of polymeric materials such as ioniccopolymers of ethylene and an unsaturated monocarboxylic acid which areavailable under the trademark “SURLYN®” of E. I. DuPont De Nemours &Company of Wilmington, Del. or “IOTEK®” or “ESCOR®” from Exxon ofHouston, Tex. These are copolymers of ethylene and methacrylic acid oracrylic acid partially neutralized with zinc, sodium, lithium,magnesium, potassium, calcium, manganese, nickel or the like.

In accordance with the various embodiments of the present invention, thecover 11 has a thickness to generally provide sufficient strength, goodperformance characteristics and durability. Preferably, the cover 11 isof a thickness from about 0.015 inches to about 0.12 inches. Morepreferably, the cover 11 is about 0.020 to 0.09 inches in thickness and,most preferably, is about 0.025 to 0.085 inches in thickness.

In accordance with a preferred embodiment of this invention, the cover11 can be formed from mixtures or blends of zinc, magnesium, calcium,potassium, lithium and/or sodium ionic copolymers. The SURLYN® resinsfor use in the cover 11 are ionic copolymers in which sodium, lithium orzinc salts are the reaction product of an olefin having from 2 to 8carbon atoms and an unsaturated monocarboxylic acid having 3 to 8 carbonatoms. The carboxylic acid groups of the copolymer may be totally orpartially neutralized and might include acrylic, methacrylic, crotonic,maleic, fumaric or itaconic acid.

The golf balls and components (e.g., cover layers, mantle layers, and/orcore layers) encompassed by this invention can likewise be used inconjunction with homopolymeric and copolymeric materials, such as:

(1) Vinyl resins such as those formed by the polymerization of vinylchloride, or by the copolymerization of vinyl chloride with vinylacetate, acrylic esters or vinylidene chloride;

(2) Polyolefins such as polyethylene, polypropylene, polybutylene andcopolymers such as ethylene methylacrylate, ethylene ethylacrylate,ethylene vinyl acetate, ethylene methacrylic or ethylene acrylic acid orpropylene acrylic acid and copolymers and homopolymers produced usingsingle-site catalyst;

(3) Polyurethanes such as those prepared from polyols and diisocyanatesor polyisocyanates and those disclosed in U.S. Pat. No. 5,334,673;

(4) Polyureas such as those disclosed in U.S. Pat. No. 5,484,870;

(5) Polyamides such as poly(hexamethylene adipamide) and others preparedfrom diamines and dibasic acids, as well as those from amino acids suchas poly(caprolactam), and blends of polyamides with SURYLN®,polyethylene, ethylene copolymers, ethyl-propylene-non-conjugated dieneterpolymer, and the like;

(6) Acrylic resins and blends of these resins with poly vinyl chloride,elastomers, and the like;

(7) Thermoplastics such as the urethanes, olefinic thermoplastic rubberssuch as blends of polyolefins with ethylene-propylene-non-conjugateddiene terpolymer, block copolymers of styrene and butadiene, isoprene orethylene-butylene rubber, or copoly(ether-amide), such as PEBAX® sold byAtofina of Philadelphia, Pa.;

(8) Polyphenylene oxide resins, or blends of polyphenylene oxide withhigh impact polystyrene as sold under the trademark “NORYL®” by GeneralElectric Company of Pittsfield, Mass.;

(9) Thermoplastic polyesters, such as polyethylene terephthalate,polybutylene terephthalate, polyethylene terephthalate/glycol modifiedand elastomers sold under the trademarks “HYTREL®” by E. I. DuPont DeNemours & Company of Wilmington, Del. and “LOMOD®” by General ElectricCompany, Pittsfield, Mass.;

(10) Blends and alloys, including polycarbonate with acrylonitrilebutadiene styrene, polybutylene terephthalate, polyethyleneterephthalate, styrene maleic anhydride, polyethylene, elastomers, etc.and polyvinyl chloride with acrylonitrile butadiene styrene or ethylenevinyl acetate or other elastomers; and

(11) Blends of thermoplastic rubbers with polyethylene, propylene,polyacetal, nylon, polyesters, cellulose esters, and the like.

Additional materials may be included in the compositions of the coverlayers, mantle layers, and/or core layers outlined above. For example,reaction enhancers, catalysts, coloring agents, optical brighteners,crosslinking and co-crosslinking agents, whitening agents such as TiO₂and ZnO, UV absorbers, hindered amine light stabilizers, defoamingagents, processing aids, surfactants, and other conventional additivesmay be added to the compositions. In addition, antioxidants,stabilizers, softening agents, plasticizers, including internal andexternal plasticizers, impact modifiers, foaming agents,density-adjusting fillers, reinforcing materials, and compatibilizersmay also be added to any of the cover and/or mantle layer compositions.One of ordinary skill in the art should be aware of the requisite amountfor each type of additive to realize the benefits of that particularadditive.

In a preferred embodiment, the cover 11 is comprised of polymers such asethylene, propylene, butene-1 or hexane-1 based homopolymers andcopolymers including functional monomers such as acrylic and methacrylicacid and fully or partially neutralized ionomer resins and their blends,methyl acrylate, methyl methacrylate homopolymers and copolymers,imidized, amino group containing polymers, polycarbonate, reinforcedpolyamides, polyphenylene oxide, high impact polystyrene, polyetherketone, polysulfone, poly(phenylene sulfide), acrylonitrile-butadiene,acrylic-styrene-acrylonitrile, poly(ethylene terephthalate),poly(butylene terephthalate), poly(ethylene vinyl alcohol),poly(tetrafluoroethylene) and their copolymers including functionalcomonomers and blends thereof. Still further, the cover 11 is preferablycomprised of a polyether or polyester thermoplastic urethane, athermoset polyurethane, a low modulus ionomer such as acid-containingethylene copolymer ionomers, including E/X/Y copolymers where E isethylene, X is an acrylate or methacrylate-based softening comonomerpresent in 0-50 weight percent and Y is acrylic or methacrylic acidpresent in 5-35 weight percent. More preferably, in a low spin rateembodiment designed for maximum distance, the acrylic or methacrylicacid is present in 15-35 weight percent, making the ionomer a highmodulus ionomer. In a high spin embodiment, the acid is present in 10-15weigh percent or a blend of a low modulus ionomer with a standardionomer is used.

In another preferred embodiment, the cover 11 is comprised of polyureaor a polyurethane/polyurea hybrid, such as those disclosed in U.S. Pat.No. 6,835,794. The polyurea or a polyurethane/polyurea hybrid may bealiphatic, aromatic or a combination thereof. In a preferred embodiment,the cover 11 is formed from a polyurea composition including at leastone light stable or saturated polyurea. Light stability may beaccomplished in a variety of ways, such as by utilizing polyureacompositions that include only saturated components, i.e., saturatedprepolymers and saturated curing agents, or include a light stabilizerto improve light stability when using aromatic components. The lightstable or saturated polyurea includes from about 1 to about 100 weightpercent of the cover, with the remainder of the cover, if any, includingone or more compatible, resilient polymers such as would be known to oneof ordinary skill in the art.

The polyurea compositions may be prepared from at least one isocyanate,at least one polyether amine, and at least one curing agent. Preferablythe at least one curing agent is a diol or secondary diamine curingagent.

In another embodiment, the polyether or polyester thermoplasticurethane, thermoset polyurethane, polyurea, or polyurethane/polyureahybrid is formed from an isocyanate prepolymer (also referred to hereinas “isocyanate”). Any isocyanate available to one of ordinary skill inthe art is suitable for use according to the invention. Isocyanates foruse with the present invention include aliphatic, cycloaliphatic,araliphatic, aromatic, any derivatives thereof, and combinations ofthese compounds having two or more isocyanate (NCO) groups per molecule.The isocyanates may be organic polyisocyanate-terminated prepolymers,low free isocyanates, and mixtures thereof. The isocyanate-containingreactable component may also include any isocyanate-functional monomer,dimer, trimer, or multimeric adduct thereof, prepolymer,quasi-prepolymer, or mixtures thereof. Isocyanate-functional compoundsmay include monoisocyanates or polyisocyanates that include anyisocyanate functionality of two or more.

The compositions of the present invention also encompass polyurethanesformed from a blend of diisocyanate prepolymers, such as those disclosedin U.S. Pat. No. 6,569,034 to Dewanjee et al, the entire disclosure ofwhich is incorporated herein by reference. The compositions of thepresent invention also encompass polyurethanes formed from paraphenylenediisocyanate-based polyurethane prepolymer, as disclosed in U.S. Pat.No. 6,117,024 to Dewanjee et al, the entire disclosure of which isincorporated herein by reference.

In a preferred embodiment, the isocyanate is a saturated or unsaturateddiisocyanate including, for example, diisocyanates having the genericstructure: O═C═N—R—N═C═O, where R is a cyclic, aromatic, aliphatic,linear, branched, or substituted hydrocarbon moiety containing fromabout 1 to 20 carbon atoms, such as arylenes, aralkylenes, alkylenes, orcycloalkylenes. When multiple cyclic or aromatic groups are present,linear, branched, or substituted hydrocarbons containing from about 1 to10 carbon atoms can be present as spacers between the cyclic or aromaticgroups. In some cases, the cyclic or aromatic group(s) may besubstituted at the 2-, 3-, and/or 4-positions, respectively. Substitutedgroups may include, but are not limited to, halogens, cyano groups,amine groups, silyl groups, hydroxyl groups, acid groups, alkoxy groups,primary, secondary, or tertiary hydrocarbon groups, or a mixturethereof.

Examples of saturated (aliphatic) diisocyanates that can be used in thepolyurethane prepolymer include, but are not limited to, ethylenediisocyanate; propylene-1,2-diisocyanate; tetramethylene diisocyanate;1,4-tetramethylene diisocyanate; 1,5-pentamethylene diisocyanate;2-methyl-1,5-pentamethylene diisocyanate; 1,6-hexamethylene diisocyanate(HDI); HDI biuret prepared from HDI; octamethylene diisocyanate;decamethylene diisocyanate; 2,2,4-trimethylhexamethylene diisocyanate;2,4,4-trimethylhexamethylene diisocyanate; 1,7-heptamethylenediisocyanate; 1,8-octamethylene diisocyanate; 1,9-novamethylenediisocyanate; 1,10-decamethylene diisocyanate; 1,12-dodecanediisocyanate; 1,3-cyclobutane diisocyanate; 1,2-cyclohexanediisocyanate; 1,3-cyclohexane diisocyanate; 1,4-cyclohexanediisocyanate; methylcyclohexylene diisocyanate (HTDI);2,4-methylcyclohexane diisocyanate; 2,6-methylcyclohexane diisocyanate;4,4′-dicyclohexane diisocyanate; 2,4′-dicyclohexane diisocyanate;1,3,5-cyclohexane triisocyanate; isocyanatomethylcyclohexane isocyanate;1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane;isocyanatoethylcyclohexane isocyanate; bis(isocyanatomethyl)-cyclohexanediisocyanate; 4,4′-bis(isocyanatomethyl) dicyclohexane;2,4′-bis(isocyanatomethyl) dicyclohexane; isophorone diisocyanate(IPDI); triisocyanate of HDI; triisocyanate of2,2,4-trimethyl-1,6-hexane diisocyanate (TMDI); 4,4′-dicyclohexylmethanediisocyanate (H₁₂MDI); 2,4-hexahydrotoluene diisocyanate;2,6-hexahydrotoluene diisocyanate; aromatic aliphatic isocyanate, suchas 1,2-, 1,3-, and 1,4-xylene diisocyanate; meta-tetramethylxylenediisocyanate (m-TMXDI); para-tetramethylxylene diisocyanate (p-TMXDI);saturated trimerized isocyanurates, such as isocyanurates ofhexamethylene diisocyanate, isocyanurates of isophorone diisocyanate,HDI biurets prepared from HDI, isocyanurates of trimethylhexamethylenediisocyanate, and mixtures thereof; uretdione of hexamethylenediisocyanate, and mixtures thereof; modified polyisocyanate derived fromthe above isocyanates and polyisocyanates; and mixtures thereof.

Unsaturated diisocyanates, i.e., aromatic compounds, may also be usedwith the present invention, although the use of unsaturated compounds inthe prepolymer is preferably coupled with the use of a light stabilizeror pigment as discussed below. Examples of unsaturated diisocyanatesinclude, but are not limited to, substituted and isomeric mixturesincluding 2,2′-, 2,4′-, and 4,4′-diphenylmethane diisocyanate (MDI);2,2′-, 2,4′-, and 4,4′-biphenylene diisocyanate;3,3′-dimethyl-4,4′-biphenyl diisocyanate (TODI);3,3′-dimethyl-4,4′-diphenylmethane diisocyanate; toluene diisocyanate(TDI); polymeric MDI (PMDI, a brown liquid composed of approximately 50%methylene diisocyanate with the remainder comprised of oligomers ofMDI); carbodimide-modified liquid 4,4′-diphenylmethane diisocyanate;para-phenylene diisocyanate (PPDI); meta-phenylene diisocyanate (MPDI);ortho-phenylene diisocyanate; 4-chloro-1,3-phenylene diisocyanate;triphenylmethane-4,4′-, and triphenylmethane-4,4″-triisocyanate;1,5-naphthalene diisocyanate; 1,5-tetrahydronaphthalene diisocyanate;anthracene diisocyanate; tetracene diisocyanate; dimerized uretdiones ofany diisocyanate or polyisocyanate, such as uretdione of toluenediisocyanate, uretdione of diphenylmethane diisocyanate, and mixturesthereof; unsaturated trimerized isocyanurates, such as trimers ofdiphenylmethane diisocyanate, trimers of tetramethylxylene diisocyanate,isocyanurates of toluene diisocyanate, and mixtures thereof; monomerictriisocyanates such as 2,4,4′-diphenylene triisocyanate,2,4,4′-diphenylmethane triisocyanate, 4,4′,4″-triphenylmethanetriisocyanate, and mixtures thereof; and mixtures thereof.

Any polyether amine available to one of ordinary skill in the art issuitable for use according to the invention. As used herein, “polyetheramines” refer to at least polyoxyalkyleneamines containing primary aminogroups attached to the terminus of a polyether backbone. Due to therapid reaction of isocyanate and amine, and the insolubility of manyurea products, however, the selection of diamines and polyether aminesis limited to those allowing the successful formation of the polyureaprepolymers. In one embodiment, the polyether backbone is based ontetramethylene, propylene, ethylene, trimethylolpropane, glycerin, andmixtures thereof.

The polyurea composition can be formed by crosslinking the polyureaprepolymer with a blend or mixture of curing agents. Curing agents foruse with the present invention include, but are not limited to, hydroxyterminated curing agents, amine-terminated curing agents, and mixturesthereof. In one preferred embodiment, the curing agents areamine-terminated curing agents, and more preferably secondary diaminecuring agents. If desired, however, the polyurea composition may beformed with a single curing agent. Polyurea prepolymers cured with asecondary diamine with 1:1 stoichiometry in the absence of moisture arethermoplastic in nature, while thermoset polyurea compositions, on theother hand, are generally produced from a polyurea prepolymer cured witha primary diamine or polyfunctional glycol.

The use of light stabilizing components also may assist in preventingcover surface fractures due to photodegredation. Suitable UV absorbersand light stabilizers include, but are not limited to, TINUVIN® 292,TINUVIN® 328, TINUVIN® 213, TINUVIN® 765, TINUVIN® 770 and TINUVIN® 622.The preferred UV absorber for aromatic compounds is TINUVIN® 328, andthe preferred hindered amine light stabilizer is TINUVIN® 765. Apreferred light stabilizer for the saturated (aliphatic) compounds isTINUVIN® 292. TINUVIN® products are available from Ciba-Geigy. Dyes, aswell as optical brighteners and fluorescent pigments may also beincluded in the golf ball covers produced with polymers formed accordingto the present invention. Such additional ingredients may be added inany amounts that will achieve their desired purpose.

The compositions of the present invention may be selected from amongboth castable thermoset and thermoplastic materials, which is determinedby the curing agent used to cure the prepolymer. For example, castablethermoplastic compositions of the invention include linear polymers andare typically formed curing the prepolymer with a diol or secondarydiamine. Thermoset compositions of the invention, on the other hand, arecross-linked polymers and are typically produced from the reaction of adiisocyanate and a polyol cured with a primary diamine or polyfunctionalglycol.

The polyurea compositions preferably include from about 1 percent toabout 100 percent polyurea, however, the polyurea compositions may beblended with other materials. In one embodiment, the compositioncontains about 10 percent to about 90 percent polyurea, preferably fromabout 10 percent to about 75 percent polyurea, and contains about 90percent to 10 percent, more preferably from about 90 percent to about 25percent other polymers and/or other materials as described below.

Other polymeric materials suitable for blending with the compositions ofthe invention include castable thermoplastic or thermoset polyurethanes,cationic and anionic urethane ionomers and urethane epoxies,polyurethane/polyurea ionomers, epoxy resins, polyethylenes, polyamidesand polyesters, polycarbonates, polyacrylin, and mixtures thereof.Examples of suitable urethane ionomers are disclosed in U.S. Pat. No.5,692,974, the entire disclosure of which is incorporated by referenceherein. Other examples of suitable polyurethanes are described in U.S.Pat. No. 5,334,673, the entire disclosure of which is incorporated byreference herein. Examples of suitable polyureas used to form thepolyurea ionomer listed above are discussed in U.S. Pat. No. 5,484,870,the entire disclosure of which is incorporated by reference herein. Inparticular, the polyureas of U.S. Pat. No. 5,484,870 are prepared byreacting a polyisocyanate and a polyamine curing agent to yieldpolyurea, which are distinct from the polyureas mentioned above, whichare formed from a polyurea prepolymer and curing agent. Examples ofsuitable polyurethanes cured with epoxy group containing curing agentsare disclosed in U.S. Pat. No. 5,908,358, the entire disclosure of whichis incorporated by reference herein.

Thus in a preferred embodiment, polyurea compositions are blended withpolyurethane to form a polyurea/polyurethane hybrid. Polyurethanessuitable for use in the invention are the product of a reaction betweenat least one polyurethane prepolymer and at least one curing agent. Thepolyurethanes used in the compositions of the present invention may beselected from among both castable thermoset and thermoplasticpolyurethanes. Thermoplastic polyurethanes are linear polymers and aretypically formed from the reaction of a diisocyanate and a polyol curedwith a diol or a secondary diamine with 1:1 stoichiometry in the absenceof moisture. Thermoset polyurethanes, on the other hand, are crosslinkedpolymers and are typically produced from the reaction of a diisocyanateand a polyol cured with a primary diamine or polyfunctional glycol.

Additionally, suitable cover materials include a nucleated reactioninjection molded polyurethane, polyurea or polyurea/polyurethanehybrids, where a gas, typically an inert or non-reactive gas such asnitrogen, argon, helium and air, is essentially vigorously mixed into atleast one component of the polyurethane, typically, the pre-polymer,prior to component injection into a closed mold where full reactiontakes place resulting in a cured polymer having reduced specificgravity. The materials are referred to as reaction injection molded(“RIM”) materials. Examples of RIM materials, as well as the RIMprocess, are disclosed in U.S. Pat. Nos. 6,548,618, 6,533,566 and6,290,614, the entire disclosures of which are incorporated herein byreference.

In the mantle portion 16, the liquid center shell 20, and first andsecond mantle layers 22 and 40 are preferably made of elastomers, suchas thermoset rubber, including polyisoprene, styrene butadiene,polybutadiene and combinations thereof; plastic, such as polypropylene;or thermoplastic elastomeric material such as copolymers ofmethyl-methacrylate with butadiene and styrene, copolymers ofmethyl-acrylate with butadiene and styrene, acrylonitrile styrenecopolymers, polyether-ester, polyether-amide, polyurethane and/or blendsthereof. Most preferably, the first and second mantle layers 22 and 40are made of thermoset rubber or thermoplastic elastomeric materials.

In another embodiment, highly-neutralized polymers (“HNP's”) and blendsthereof, such as those described in U.S. patent application Ser. No.10/118,719, filed Apr. 9, 2002, now U.S. Pat. No. 6,756,436, and U.S.patent application Ser. No. 10/959,751, filed Oct. 6, 2004, now U.S.Publication No. 2005/0049367, the entire disclosures of which areincorporated by reference herein, as well as low melting thermoplastics,may be used in ball cores, mantle layers, and/or covers. HNP's includepolymers containing one or more acid groups that are neutralized by anorganic acid or a salt thereof. In a preferred embodiment, the first andsecond mantle layers 22 and 40 are made of such highly-neutralizedpolymers and/or low melting thermoplastics. In one embodiment, the lowmelting thermoplastics have a resilience of a thermoset rubber. Forexample, such low melting thermoplastics having a resilience of athermoset rubber include, but are not limited to, HNP's and blends ofHNP's with compatible thermoplastics, such as partially or fullyneutralized ionomers including those neutralized by a metal ion sourcewherein the metal ion is the salt of an organic acid, polyolefinsincluding polyethylene, polypropylene, polybutylene, and copolymersthereof including polyethylene acrylic acid or methacrylic acidcopolymers, or a terpolymer of ethylene, a softening acrylate classester such as methyl acrylate, n-butyl-acrylate or iso-butyl-acrylate,and a carboxylic acid such as acrylic acid or methacrylic acid (e.g.,terpolymers including polyethylene-methacrylic acid-n or iso-butylacrylate and polyethylene-acrylic acid-methyl acrylate, polyethyleneethyl or methyl acrylate, polyethylene vinyl acetate, polyethyleneglycidyl alkyl acrylates).

The acid moieties of the HNP's, typically ethylene-based ionomers, areneutralized greater than about 70%, preferably greater than about 80%,more preferably greater than about 90%, and most preferably at leastabout 100%. The HNP's can be also be blended with a second polymercomponent, which, if containing an acid group, may be neutralized in aconventional manner, by the organic fatty acids, or both. The secondpolymer component, which may be partially or fully neutralized,preferably comprises ionomeric copolymers and terpolymers, ionomerprecursors, thermoplastics, polyamides, polycarbonates, polyesters,polyurethanes, polyureas, thermoplastic elastomers, polybutadienerubber, balata, metallocene-catalyzed polymers (grafted andnon-grafted), single-site polymers, high-crystalline acid polymers,cationic ionomers, and the like. HNP polymers typically have a materialhardness of between about 20 and about 80 Shore D, and a flexuralmodulus of between about 3,000 psi and about 200,000 psi.

In one embodiment, the organic acid is selected from the groupconsisting of aliphatic organic acids, aromatic organic acids, saturatedmono-functional organic acids, unsaturated mono-functional organicacids, and multi-unsaturated mono-functional organic acids. Preferably,the salt of organic acids comprise the salts of barium, lithium, sodium,zinc, bismuth, chromium, cobalt, copper, potassium, strontium, titanium,tungsten, magnesium, cesium, iron, nickel, silver, aluminum, tin,calcium, stearic, behenic, erucic, oleic, linoelic, dimerizedderivatives, and mixtures thereof.

Additionally, HNP's, such as those described in U.S. application Ser.No. 11/270,066, filed Nov. 9, 2005, the entire disclosure of which isincorporated by reference herein, may be used in the ball cores, mantlelayers and/or covers. For example, it has been found that when an acidpolymer or a partially neutralized acid polymer is neutralized to 70% orhigher using a cation source which is less hydrophilic thanmagnesium-based cation sources traditionally used to produce HNPs, theresulting inventive HNP provides for compositions having improvedmoisture vapor transmission properties. For example, a polymercomposition comprising an HNP, wherein the HNP is produced using a lesshydrophilic cation source, can have a moisture vapor transmission rateof 8 g-mil/100in²/day or less, or 5 g-mil/100in²/day or less, or 3g-mil/100in²/day or less, or 2 g-mil/100in²/day or less, or 1g-mil/100in²/day or less, or less than 1 g-mil/100in²/day. As usedherein, moisture vapor transmission rate (MVTR) is given in g-mil/100in²/day, and is measured at 20° C., and according to ASTM F1249-99.

“Less hydrophilic” is used herein to refer to cation sources which areless hydrophilic than conventional magnesium-based cation sources.Examples of suitable less hydrophilic cation sources include, but arenot limited to, silicone, silane, and silicate derivatives and complexligands; metal ions and compounds of rare earth elements; and lesshydrophilic metal ions and compounds of alkali metals, alkaline earthmetals, and transition metals; and combinations thereof. Particular lesshydrophilic cation sources include, but are not limited to, metal ionsand compounds of potassium, cesium, calcium, barium, manganese, copper,zinc, tin, and rare earth metals. Potassium-based compounds are apreferred less hydrophilic cation source, and particularly Oxone®,commercially available from E. I. du Pont de Nemours and Company. Oxone®is a monopersulfate compound wherein potassium monopersulfate is theactive ingredient present as a component of a triple salt of the formula2KHSO₅.KHSO₄.K₂SO₄ [potassium hydrogen peroxymonosulfate sulfate(5:3:2:2)]. The amount of less hydrophilic cation source used is readilydetermined based on the desired level of neutralization.

In one embodiment, the first and second mantle layers 22 and 40 eachindependently can include a crosslinker, such as a metal salt ofunsaturated carboxylic acid. In particular, the metal salt ofunsaturated carboxylic acid is blended as a co-crosslinking agent in atleast one of the first and second mantle layer 22 and 40. Examplesinclude magnesium, calcium, zinc, aluminum, sodium, lithium, or nickelsalts of unsaturated fatty acids having 3 to 8 carbon atoms, such asacrylic acid, methacrylic acid, maleic acid, and fumaric acid, with thezinc salts of acrylic and methacrylic acid being most preferred.Preferred metal salts of unsaturated fatty acids include zinc acrylate,zinc diacrylate, zinc methacrylate, zinc dimethacrylate, and mixturesthereof. The unsaturated carboxylic acid metal salt may be blended in arubber either as a preformed metal salt or by introducing anα,β-unsaturated carboxylic acid and a metal oxide or hydroxide into therubber composition and allowing them to react in the rubber compositionto form a metal salt. The unsaturated carboxylic acid metal salt may beblended in any desired amount, but preferably in amounts of about 25 toabout 40 parts and more preferably between about 30 to about 35 byweight per 100 parts by weight of the base rubber.

The composition of the first or second mantle layer (22 or 40) may alsocontain an organosulfur compound or a metal salt thereof in addition tothe base rubber and the unsaturated carboxylic acid metal salt, such asthose disclosed in copending U.S. patent application Ser. No. 09/951,963(now U.S. Pat. No. 6,635,716), the entirety of which is incorporatedherein by reference. The addition of such organosulfur compounds to baserubber compositions exhibit increased COR, decreased compression, orboth. The organosulfur compound or metal salt thereof is preferably ahalogenated organosulfur compound, and more preferably a halogenatedthiophenol, including, but not limited to, pentafluorothiophenol;2-fluorothiophenol; 3-fluorothiophenol; 4-fluorothiophenol;2,3-fluorothiophenol; 2,4-fluorothiophenol; 3,4-fluorothiophenol;3,5-fluorothiophenol 2,3,4-fluorothiophenol; 3,4,5-fluorothiophenol;2,3,4,5-tetrafluorothiophenol; 2,3,5,6-tetrafluorothiophenol;4-chlorotetrafluorothiophenol; pentachlorothiophenol;2-chlorothiophenol; 3-chlorothiophenol; 4-chlorothiophenol;2,3-chlorothiophenol; 2,4-chlorothiophenol; 3,4-chlorothiophenol;3,5-chlorothiophenol; 2,3,4-chlorothiophenol; 3,4,5-chlorothiophenol;2,3,4,5-tetrachlorothiophenol; 2,3,5,6-tetrachlorothiophenol;pentabromothiophenol; 2-bromothiophenol; 3-bromothiophenol;4-bromothiophenol; 2,3-bromothiophenol; 2,4-bromothiophenol;3,4-bromothiophenol; 3,5-bromothiophenol; 2,3,4-bromothiophenol;3,4,5-bromothiophenol; 2,3,4,5-tetrabromothiophenol;2,3,5,6-tetrabromothiophenol; pentaiodothiophenol; 2-iodothiophenol;3-iodothiophenol; 4-iodothiophenol; 2,3-iodothiophenol;2,4-iodothiophenol; 3,4-iodothiophenol; 3,5-iodothiophenol;2,3,4-iodothiophenol; 3,4,5-iodothiophenol; 2,3,4,5-tetraiodothiophenol;2,3,5,6-tetraiodothiophenoland; and their zinc salts. Preferably, thehalogenated thiophenol is pentachlorothiophenol (“PCTP”), which iscommercially available in neat form or under the tradename STRUKTOL®, aclay-based carrier containing the sulfur compound pentachlorothiophenolloaded at 45 percent (correlating to 2.4 parts PCTP). STRUKTOL® iscommercially available from Struktol Company of America of Stow, Ohio.PCTP is commercially available in neat form from eChinachem of SanFrancisco, Calif. and in the salt form from eChinachem of San Francisco,Calif. Most preferably, the halogenated thiophenol is the zinc salt ofpentachlorothiophenol, which is commercially available from eChinachemof San Francisco, Calif. The organosulfur compounds of the presentinvention are present in any amount, preferably in an amount greaterthan about 2 parts or less than 40 parts by weight per 100 parts of baserubber (“pph”). In one embodiment, the organosulfur compound is presentbetween about 2.2 pph and about 30 pph, and preferably between about 2.3and about 20 pph. In another embodiment, the organosulfur compound ispresent from about 2.5 pph to about 15 pph, preferably between about 5pph to about 10 pph. The upper and lower limits of the ranges disclosedherein are interchangeable to form new ranges. For example, the amountof organosulfur compound may be present between about 2.2 pph to about15, or between about 10 pph and about 40 pph, or between about 2 pph toabout 5 pph.

The composition of the first or second mantle layer (20 or 40) mayfurther contain a co-crosslinking initiator. Preferred examples of theco-crosslinking initiator include organic peroxides, such as dicumylperoxide, t-butylperoxybenzoate, di-t-butylperoxide,1,1-bis(t-butylperoxy)-3,3,5 trimethyl-cyclohexane,n-butyl-4,4-bis(t-butylperoxy)valerate,2,2,-bis(t-butylperoxy-isopropyl)benzene, and2,5-dimethyl-2,5-di(t-butylperoxy)hexene, with the dicumyl peroxidebeing most preferred. The initiator may be blended in amounts of about0.5 to about 3 parts by weight, preferably about 1 to about 2.5 parts byweight per 100 parts by weight of the base rubber.

A composite or metal layer may also be utilized for the first or secondmantle layer (22 or 40) as described in U.S. Pat. No. 6,899,642, theentire disclosure of which is incorporated by reference herein. Forexample, the composite material may include a filament material embeddedin a matrix or binder material.

The filament material may be a single fiber or formed of more than onefiber or a plurality of fibers (i.e., multi-fiber tow or bundle). Thefilament material may be formed of fibers of polymeric materials, glassmaterials, or metal fibers, among others. The filament material may alsobe comprised of strands or fibers having different physical propertiesto achieve desired stretch and elongation characteristics. The matrixmaterial may be molded about the filament material so that the filamentmaterial is embedded in the matrix material, as discussed above. Thematrix material may be a thermoset or a thermoplastic polymer. Preferredthermoset polymeric materials are, for example, unsaturated polyesterresins, vinyl esters, epoxy resins, phenolic resins, polyurethanes,polyurea, polyimide resins, and polybutadiene resins. Preferredthermoplastics are, for example, polyethylene, polystyrene,polypropylene, thermoplastic polyesters, acrylonitrile butadiene styrene(ABS), acetal, polyamides including semicrystalline polyamide,polycarbonate (PC), shape memory polymers, polyvinyl chloride (PVC),polyurethane, trans-polybutadiene, liquid crystalline polymers,polyether ketone (PEEK), bio(maleimide), and polysulfone resins.

The matrix material can also be a silicone material, such as a siliconepolymer, a silicone elastomer, a silicone rubber, silicone resins, or alow molecular weight silicone fluid, thermoplastic silicone urethanecopolymers and variations, and the likes.

In one embodiment, preferably, the first mantle layer 22 is comprised ofpolybutadiene material that has high specific gravity for a low spinrate ball and a low specific gravity for a high spin rate ball. Thespecific gravity of the polybutadiene material can be varied by addingfillers known to those skilled in the art.

In another embodiment, the mantle portion 16 is relatively thick and iscomprised of a highly neutralized ionomer or a crosslinked polybutadienerubber.

In one embodiment, the mantle portion 16 preferably has an outsidediameter d3 in the range of 80 to 98% of the finished ball diameter Dand an inner diameter d1 in the range of 30 to 70% of the finished balldiameter. Preferably, mantle portion 16 and the liquid center shell 20have an inner diameter of approximately 0.5 to 1.18 inches and, morepreferably, an inner diameter of approximately 0.75 to 1.1 inches.Preferably, the mantle portion 16 and liquid center shell 20 have aninner diameter of approximately 0.9 to 0.95 inches. The first mantlelayer 22 preferably has an inner diameter d2 in the range of 0.55 to1.45 inches and, more preferably, approximately 0.8 to 1.3 inches. Yetfurther still, the mantle portion 16 has an outside diameter d3 in therange of 1.3 to 1.65 inches and, more preferably, approximately 1.45 to1.62 inches.

In another embodiment, preferably, the mantle portion 16 and the liquidcenter shell 20 have an inner diameter d1 of approximately 0.25 to 1.5inches and, more preferably, an inner diameter of approximately 0.5 to1.35 inches. Preferably, the mantle portion 16 and the liquid centershell 20 have an inner diameter of approximately 0.65 to 1.25 inches.The mantle portion 16 preferably has a thickness of 0.04 to 0.35 inches,and more preferably 0.07 to 0.3 inches and may comprise one or morelayers or plys of the same or different materials.

A golf ball incorporating these measurements can be designed with thevarious attributes discussed below, such as specific gravity, resiliencyand hardness, to provide the desired playing characteristics, such asspin rate and initial velocity. More particularly, by using a liquidcenter shell to surround the fluid center, in an inner sphere, and atleast a first mantle layer, the specific gravities and other propertiescan be tailored to provide optimum playing characteristics. Moreparticularly, by constructing a ball according to these dimensions, thefirst mantle layer 22 is made with a significant volume compared to thefluid center 18. Preferably, the volume of the first mantle layer 22 isgreater than the volume of the fluid center 18. More preferably, thevolume of the first layer 22 is about 2 to 4 times the volume of thefluid center 18. Thus, the properties of the first mantle layer caneffect the playing characteristics of the ball.

The hardness and resiliency of the mantle portion 16 can be varied toachieve certain desired parameters such as spin rate, compression andinitial velocity.

Preferably, the mantle portion 16 has a hardness of approximately 30 to95 Shore C, and more preferably, 45 to 90 Shore C. Still further, themantle portion 16 has a resiliency greater than 40 Bashore.

In a most preferred embodiment, the liquid center shell 20 is comprisedof a plastic material having high temperature resistance, such as thosedisclosed in U.S. patent application Ser. No. 10/008,013, filed Nov. 13,2001, now U.S. Pat. No. 6,616,549. In particular, the liquid centershell 20 and/or the first mantle layer 22 comprises dynamicallyvulcanized thermoplastic elastomer; functionalized styrene-butadieneelastomer; thermoplastic polyurethane; thermoplastic polyetherester orpolyetheramide; thermoplastic ionomer resin; fluoro-polymers, such asperfluoroalkylenes (e.g., polytetrafluoroethylene,polyhexafluoropropylene), and functionalized fluoropolymer resins thatare sulfonated, carboxylated, epoxidized, maleated, amined orhydroxylized as disclosed in U.S. Pat. No. 5,962,140, the entirety ofwhich is incorporated by reference herein; thermoplastic polyester;metallocene polymer or blends thereof and/or thermoset materials.

It will be appreciated that the wall material may be any material knownthe in art, including thermoplastic-ionomer, polypropylene,polyethylene, acid copolymer, polyolefin, polyurea, metallocenecatalyzed polyolefinic copolymers, polyvinyl chloride, polytetra fluoroethylene, polyester elastomer, polyamide elastomer, polycarbonate,polyester, styrene-butadiene and SEBS block copolymers, silicone orthermoset crosslinked diene rubbers, including butyl rubber, naturalrubber, and acrylonitrile.

Suitable dynamically vulcanized thermoplastic elastomers includeSANTOPRENE®, SARLINK®, VYRAM®, DYTRON® and VISTAFLEX®. SANTOPRENE® isthe trademark for a dynamically vulcanized PP/EPDM(polypropylene/ethylene-propylene-diene rubber). SANTOPRENE® 203-40 isan example of a preferred SANTORPENE® and is commercially available fromAdvanced Elastomer Systems, Akron, Ohio. Examples of suitablefunctionalized styrene-butadiene elastomers include KRATON® FG-1901x andKRATON® FG-1921x, which are available from the Shell Corporation.Examples of suitable thermoplastic polyurethanes include ESTANE® 58133,ESTANE® 58134 and ESTANE® 58144, which are commercially available fromthe B. F. Goodrich Company. Suitable metallocene polymers whose meltingpoints are higher than the cover materials can also be employed in themantle layer of the present invention. Further, the materials for themantle layer described above may be in the form of a foamed polymericmaterial. For example, suitable metallocene polymers include foams ofthermoplastic elastomers based on metallocene single-site catalyst-basedfoams. Such metallocene-based foam resins are commercially availablefrom Sentinel Products of Hyannis, Mass.

Suitable thermoplastic polyetheresters include HYTREL® 3078, HYTREL®3548, HYTREL® 4078, HYTREL® 4069, HYTREL® 6356, HYTREL® 7246, andHYTREL® 8238 which are commercially available from DuPont, Wilmington,Del. Suitable thermoplastic polyetheramides include PEBAX® 2533, PEBAX®3533, PEBAX® 4033, PEBAX® 5533, PEBAX® 6333, and PEBAX® 7033 which areavailable from Atofina, Philadelphia, Pa. Suitable thermoplastic ionomerresins include any number of olefinic based ionomers including SURLYN®and IOTEKI®, which are commercially available from DuPont and Exxon,respectively. The flexural moduli for these ionomers are about 1000 psito about 200,000 psi. Suitable thermoplastic polyesters includepolybutylene terephthalate. Likewise, the dynamically vulcanizedthermoplastic elastomers, functionalized styrene-butadiene elastomers,thermoplastic polyurethane or metallocene polymers identified above arealso useful as the second thermoplastic in such blends. Further, thematerials of the second thermoplastic described above may be in the formof a foamed polymeric material.

Preferably, the shell 20 is a thin layer of a polyolefin, ionomer oracid copolymer. Alternatively, the shell 20 may be made of aconventional wound envelope material. In yet another embodiment, theshell 20 material may include a HNP material, as described above.Preferably, this HNP would be selected from those disclosed in U.S.application Ser. No. 11/270,066, filed Nov. 9, 2005, the entiredisclosure of which previously was incorporated by reference herein.

As illustrated in FIG. 12, the fluid center 18 may be enclosed by themantle portion 16, without a shell 20. One or more cover layers mayenclose the mantle portion 16 as described above. It will be appreciatedthat the mantle portion 16 may be comprised of one or more plys of thesame or different materials. The fluid center 18 has a diameter d1 ofapproximately 0.25 to 1.5 inches and, more preferably, a diameter ofapproximately 0.5 to 1.35 inches. The mantle portion 16 preferably has athickness of 0.4 to 0.8 inches, and more preferably 0.4 to 0.56 inches.The mantle portion 16 has an outside diameter d3 in the range of 1.3 to1.65 inches and, more preferably, approximately 1.45 to 1.62 inches. Themantle portion may be made of any material discussed previously.Preferably, the mantle portion 16 comprises HNP. Preferably, this HNPwould be selected from those disclosed in U.S. application Ser. No.11/270,066, filed Nov. 9, 2005, the entire disclosure of whichpreviously was incorporated by reference herein.

The fluid center 18 can be a wide variety of materials or fluids,including solutions and gases, as well as liquids having low coefficientof thermal expansion and/or high boiling points. In particular, thefluid center 18 may be comprised of a gas (and may be pressurized and/ornon-reactive), such as air, nitrogen, helium, argon, neon, carbondioxide, nitrous oxide and mixtures thereof; water; polyols, such asglycerine, ethylene glycol and the like; paste; foams; oils; watersolutions, such as salt in water, corn syrup, salt in water and cornsyrup, or glycol and water; or mixtures thereof. The fluid can alsoinclude pastes, colloidal suspensions, such as clay, barytes, carbonblack in water or other liquid, or salt in water/glycol mixtures; gels,such as gelatin gels, hydrogels, water/methyl cellulose gels and gelscomprised of copolymer rubber based materials such astyrene-butadiene-styrene rubber and paraffinic and/or naphthenic oil;or melts including waxes and hot melts. Hot-melts are materials which ator about normal room temperatures are solid but at elevated temperaturesbecome liquid. The fluid center 18 can also be a reactive liquid systemwhich combine to form a solid. Examples of suitable reactive liquids aresilicate gels, agar gels, peroxide cured polyester resins, two partepoxy resin systems and peroxide cured liquid polybutadiene rubbercompositions. It is understood by one skilled in the art that otherreactive liquid systems can likewise be utilized depending on thephysical properties of the liquid center shell and the physicalproperties desired in the resulting finished golf balls. U.S. Pat. Nos.6,200,230, 5,683,312, and 5,150,906 contain disclosures of preferredliquids for use in the shell 20, and their entire disclosures areincorporated by reference herein.

The fluid center 18 can be varied to modify the performance parametersof the ball, such as the moment of inertia. Preferably, the fluid center18 is comprised of a material that has a high specific gravity for highspin rate golf balls and a material that has a low specific gravity fora low spin rate golf ball. Preferably, the specific gravity of the fluidis below or equal to 1.2 for low specific gravity centers and above 1.2for high specific gravity centers. Preferably, the specific gravity isapproximately 0.90-1.2, more preferably 1.15-1.2 for low specificgravity centers and approximately 1.21-1.70, and more preferably1.3-1.55 for high specific gravity centers. Still further, the fluid ispreferably comprised of a material with a low viscosity for a golf ballhaving a high spin rate and a material having a high viscosity for agolf ball having a low spin rate. Preferably, the viscosity of the fluidcenter 18 is less than 100 cps for low viscosity centers and greaterthan or equal to 100 cps for high viscosity centers. More preferably,the viscosity of the fluid center 18 is less than or equal to 10 cps forlow viscosity centers and is between 100 and 1500 cps for high viscositycenters. Most preferably, the fluid center 18 viscosity is approximately500 cps for high viscosity centers.

The core 12 is preferably 60 to 95% of the total ball weight and morepreferably, 75 to 86% of the ball weight. As stated above, the weightdistribution within the core 12 can be varied to achieve certain desiredparameters such as spin rate, compression and initial velocity.

For example, by increasing the diameter of the fluid center 18, andincreasing the specific gravity of the mantle portion 16, the weightdistribution of the core 12 is moved toward the outer diameter for alower spin rate ball. In contrast, the diameter of the fluid center 18can be decreased and the specific gravity of the mantle layer 16decreased to move the weight distribution of the ball towards the ballcenter for a high spin rate ball.

Similarly, the specific gravity of the fluid center 18 can be decreasedand the specific gravity of the mantle portion 16 increased for a lowspin rate ball. Alternatively, the specific gravity of the fluid center18 can be increased and the specific gravity of the mantle portion 16decreased for a high spin rate ball.

Optionally, the core may have an inner surface of the shell 20 that ismodified to increase surface area and thereby change the rate of spindecay by altering the decoupling of the liquid from the shell wall atsome point following impact, as described in U.S. Pat. No. 6,238,304,the entire disclosure of which is incorporated by reference herein. Themodified inner surface allows modification of the fluid dynamicproperties in the liquid filled center by a means other then changingthe type of fluid filling in the core. More particularly, this includesuse of a modified inner surface of the shell. Frictional drag betweenthe shell and fluid is adjusted by modification of the inner surfacenext to the fluid.

Many techniques may be used to modify the frictional drag of the fluidinside the liquid center shell. A texture may be added to the innersurface of the shell. The texture could be in the form of dimples, nubs,paddles or fingers extending into the center of the core of the golfball or grooves cut or molded into the inner surface of the shell.Individual textures can themselves be modified by increasing ordecreasing their size or depth, or alternating their placement ornumber. Further, protrusions of varying sizes or shapes could be used onthe inner surface of the shell.

FIGS. 13A-D illustrate examples of shells 20 having modified innersurfaces. The shells 20 have an inner surface 80 with a texture 82added. For example, in FIG. 13A, protrusions 84 are provided on theinner surface 80 of the shell 20 to increase the surface area. Theseprotrusions 84 are shown being regularly shaped, sized and spaced. Itwill be appreciated that one or more of the shape, size and spacing ofthe protrusions may be varied. In FIG. 13B, the inner surface 80 of theshell 20 has been modified to a wavy surface to increase the surfacearea. The wavy surface may be regular or irregular. FIG. 13C illustratesthe inner surface 80 of the shell 20 having both projections 86 anddimples 88 on the inner surface 80 to increase the surface area.Finally, in FIG. 13D, the protrusions 84 are shown to be triangularprotrusions that extend from the inner surface 80 of the shell 20. Itwill be appreciated that numerous variations will be apparent to one ofskill in the art. Additionally, it will be appreciated that althoughthese modified inner surfaces 80 are illustrated on the shell 20, theycould be provided on the inner surface of any other layer providedadjacent the fluid center 18.

The modified inner surface of the shell may be used to modify the spindecay during the balls flight. Preferably, the rate of spin decay isgreater than 4% of initial spin, more preferably at least 10% of initialspin, and still more preferably at least 15% of initial spin. The rateof spin decay is preferably the rate of spin decay over the entire ballflight. For example, if a golf ball has an initial spin rate of 3500rpm, a spin decay of 10% of initial spin will result in a spin rate of3150 rpm at the end of the ball's flight.

FIGS. 14A-D illustrate the slope of a regression line quantifying therate of spin decay during the first 0.4 seconds of a ball's flight andcompare it to a similar regression quantifying the rate of spin decayfor the complete ball flight. Golf ball spin rate decay measurementswere taken on shots hit by a skilled human golfer. Measurements weremade on two wound, liquid center construction balls (Titleist TourBalata and Titleist Tour Professional), known in the prior art for theirspin decay properties. These constructions are compared to the TitleistProV1x, a modern solid construction ball known to feature a differentspin decay profile than a liquid center ball. Data was acquired by meansof a “Trackman”, a proprietary phased array radar golf ball trackingdevice manufactured by ISG Denmark (www.isg.dk). This tracking devicehas recently been used for in-tournament player data acquisition by theUSGA (http://www.usopen.com/2005/news/test_center.html). Among otherdata, Trackman provides continual real-time measurements of golf ballspin rate throughout the ball's flight. With this information, a golfball's spin rate can be plotted as a function of flight time andcomparative measurements of downrange spin performance can be evaluated.

As shown in FIGS. 14A and 14B, the spin decay for a TitleistProfessional golf ball hit by a driver is illustrated. As discussedabove, the Titleist Professional has a wound construction with a liquidcenter. This golf ball results in a regression line for the first 0.4seconds of flight having a slope of −186.83, while for the whole flightthe regression line has a slope of −87.304. Thus, the difference inslope for the two regression lines is about 100 units.

Referring now to FIG. 14C, the spin decay for a Titleist Tour Balatagolf ball hit by a driver is illustrated. As discussed above, theTitleist Tour Balata also has a wound construction with a liquid center.This golf ball results in a regression line for the first 0.4 seconds offlight having a slope of −340.18, while the regression line for thewhole flight has a slope of about −131.15. Thus, the difference in slopefor the two regression lines is about 200 units.

In comparison, FIG. 14D illustrates the spin decay for a currentTitleist ProV1x golf ball hit by a driver. As discussed above, theTitleist ProV1x has a non-wound, solid construction. This golf ballresults in a regression line for the first 0.4 seconds of flight havinga slope of −65.108, while the regression line for the whole flight has aslope of about −75.11. Thus, the difference in slope for the tworegression lines is about 10 units.

Preferably, a golf ball made according to the invention will have a rateof spin decay, such that the difference in slopes between the regressionlines of the first 0.4 seconds of golf ball flight and the whole golfball flight will be at least 20 units. More preferably, the differencein slopes will be from about 30 to 250 units. Applicants expect that agolf ball made with a liquid center, having a non-wound mantle portioncomprising HNP will result in a spin decay, such that the difference inslope for the two regression lines will be more similar to prior artgolf balls having a wound construction with a liquid center than currentsolid non-wound golf balls, such as the ProV1x.

A prophetic example of a non-wound golf ball construction possessingdesirable spin rate decay properties similar to a wound golf ball, suchas the Titleist Professional, could be achieved by providing a golf ballhaving a liquid center with a diameter of 1.125 inches. The liquidcenter may have a specific gravity of approximately 1.3 and a viscosityof approximately 1000 cps. The liquid center would be enclosed with amantle portion having a diameter of 1.580 inches and the mantle portionwould be comprised of a HNP, in a manner similar to that discussed aboveand illustrated in FIG. 12.

The distance that a golf ball would travel upon impact is a function ofthe coefficient of restitution (COR) and the aerodynamic characteristicsof the ball. The COR is defined as the ratio of the relative velocity oftwo colliding objects after the collision to the relative velocity ofthe two colliding objects prior to the collision. The COR varies from 0to 1.0. A COR value of 1.0 is equivalent to a perfectly elasticcollision, and a COR value of 0.0 is equivalent to a perfectly inelasticcollision. For golf balls, COR has been approximated as a ratio of thevelocity of the golf ball after impact to the velocity of the golf ballprior to impact. Preferably, a golf ball according to the invention hasa COR of at least 0.78, more preferably, at least 0.80.

In another embodiment, a reduced flight golf ball according to theinvention may be made. Preferably, the mantle portion 16 and the liquidcenter shell 20 have an inner diameter of approximately 0.25 to 1.5inches and, more preferably, an inner diameter of approximately 0.5 to1.35 inches. The mantle portion 16 preferably has a thickness of 0.05 to0.35 inches, and more preferably 0.07 to 0.3 inches and may comprise oneor more layers or plys of the same or different materials. Preferably,the mantle portion is comprised of HNP, as discussed previously, andmore preferably the HNP would be selected from those disclosed in U.S.application Ser. No. 11/270,066, filed Nov. 9, 2005, the entiredisclosure of which previously was incorporated by reference herein. Theshell 20 and the fluid center 18 may be comprised of any materialspreviously described herein. Alternatively, and as discussed previously,the fluid center 18 may be enclosed by the mantle portion 16, without ashell 20. Preferably, a reduced flight golf ball made according to theseembodiments will have a COR of at most 0.75, more preferably at most0.725, and most preferably at most 0.70.

According to one aspect of the present invention, the golf ball isformulated to have a compression of between about 70 and about 120.

Dimensions of golf ball components, i.e., thickness and diameter, mayvary depending on the desired properties. For the purposes of theinvention, any layer thickness may be employed. Non-limiting examples ofthe various embodiments outlined above are provided here with respect tolayer dimensions.

In one embodiment, the liquid core 12 comprises an aqueous sugarsolution housed in a polyethylene or polypropylene shell 20. The shell20 has a wall thickness of 0.03 inches and an outer diameter of 1.25inches. A mantle layer 22 covers the shell and is comprised of an HNP,such as DuPont HPF 2000. The mantle layer 22 has a thickness of 0.15inches. An inner cover layer is placed over the mantle layer andcomprises an ionomer having a flexural modulus of at least 60,000 psi.The inner cover layer has a thickness of 0.35 inches. An outer coverlayer is provided over the inner cover layer and is comprised ofpolyurethane or polyurea having a flexural modulus of less than 40,000psi. Preferably, the golf ball preferably has a COR of greater than0.78, and more preferably, greater than 0.8, and a compression of 70 to120. Preferably, the golf ball has a rate of spin decay of at least 10%of initial spin, and more preferably at least 15% of initial spin.

In another embodiment, the liquid core 12 comprises a low viscositynaphthenic oil housed in a crosslinked acrylonitrile rubber shell 20.The shell 20 has an outer diameter of 1 inch. The shell 20 is encased bya mantle layer 22 of a crosslinked polybutadiene rubber. The mantlelayer 22 has a thickness of 0.29 inches. A single cover layer 11 isprovided on the mantle layer 22. The cover 11 is comprised of an ionomeror polyurethane having a thickness of 0.05 inches and a modulus of about40,000 to 70,000 psi. Preferably, the golf ball has a COR of at least0.8 and a compression of 80 to 100. Preferably, the golf ball has a rateof spin decay of at least 10% of initial spin, and more preferably atleast 15% of initial spin.

In another embodiment, the mantle layer 22 is comprised of a HNP havinga specific gravity of 0.9. An inner cover layer is provided on themantle layer 22. The inner cover layer may be a thin dense layer asdisclosed in U.S. Pat. No. 6,743,123, the entire disclosure of which isincorporated by reference herein.

The present invention relates to golf balls of any size. While “TheRules of Golf” by the USGA dictate specifications that limit the size ofa competition golf ball to more than 1.680 inches in diameter, golfballs of any size can be used for leisure golf play. The preferreddiameter of the golf balls is from about 1.680 inches to about 1.900inches. The more preferred diameter is from about 1.680 inches to about1.760 inches. A diameter of from about 1.680 inches to about 1.740inches is most preferred; however, diameters anywhere in the range offrom 1.680 to about 1.950 inches can be used. Preferably, the overalldiameter of the core and all mantle or intermediate layers is about 80percent to about 98 percent of the overall diameter of the finishedball.

The core may have a diameter ranging from about 0.090 inches to about1.650 inches. In one embodiment, the diameter of the core of the presentinvention is about 1.200 inches to about 1.630 inches. In anotherembodiment, the diameter of the core is about 1.300 inches to about1.600 inches, preferably from about 1.390 inches to about 1.600 inches,and more preferably from about 1.500 inches to about 1.600 inches. Inyet another embodiment, the core has a diameter of about 1.550 inches toabout 1.650 inches.

The core of the golf ball may also be extremely large in relation to therest of the ball. For example, in one embodiment, the core makes upabout 90 percent to about 98 percent of the ball, preferably about 94percent to about 96 percent of the ball. In this embodiment, thediameter of the core is preferably about 1.540 inches or greater,preferably about 1.550 inches or greater. In one embodiment, the corediameter is about 1.590 inches or greater. In another embodiment, thediameter of the core is about 1.640 inches or less. Thus one embodimentencompasses golf balls having a single layer cover and a large corehaving a diameter of about 1.540 inches or greater. Another embodimentencompasses golf balls having more than one cover layers and a largecore having a diameter of about 1.540 inches or greater.

Another embodiment encompasses a golf ball having various weightdistributions of its components. Such golf balls comprise a core and acover wherein the weight or mass of the ball is allocated radiallyrelative to the centroid, thereby dictating the moment of inertia of theball. When the weight is allocated radially toward the centroid, themoment of inertia is decreased, and when the weight is allocated outwardaway from the centroid, the moment of inertia is increased.

The present invention also encompasses golf balls comprising a core anda cover wherein the weight or mass of the ball is allocated radiallyrelative to the centroid, thereby dictating the moment of inertia of theball and the golf ball may have an additional intermediate mantle and/ora cover. Distributing the weight or mass of the ball either toward theouter surface of the ball changes the dynamic characteristics of theball at impact and in flight. In particular, then the weight isallocated radially toward the centroid, the moment of inertia isdecreased, and the initial spin rate of the ball as it leaves the golfclub would increase due to lower resistance from the ball's moment ofinertia. Conversely, the weight is allocated outward away from thecentroid, the moment of inertia is increased, and the initial spin rateof the ball as it leaves the golf club would decrease due to the higherresistance from the ball's moment of inertia. Accordingly, the radialdistance from the center of the ball or from the outer cover, where themoment of inertia switches from being increased and to being decreasedas a result of the redistribution of weight or mass density, is animportant factor in golf ball design.

The moment of inertia for a one piece ball that is 1.62 ounces and 1.68inches in diameter is approximately 0.4572 oz-in², which is the baselinemoment of inertia value.

The present invention encompasses golf balls having a light center andheavy cover and mantle layers and having a moment of inertia of greaterthan 0.460 oz in². Also contemplated are golf balls having a heavy core(including center and mantle layers) and light cover layer and having amoment of inertia of less than 0.450 oz-in².

When the core includes an inner core layer and an outer core layer, theinner core layer is preferably about 0.9 inches or greater and the outercore layer preferably has a thickness of about 0.1 inches or greater. Inone embodiment, the inner core layer has a diameter from about 0.09inches to about 1.2 inches and the outer core layer has a thickness fromabout 0.1 inches to about 0.8 inches. In yet another embodiment, theinner core layer diameter is from about 0.095 inches to about 1.1 inchesand the outer core layer has a thickness of about 0.20 inches to about0.03 inches.

The cover typically has a thickness to provide sufficient strength, goodperformance characteristics, and durability. In one embodiment, thecover thickness is from about 0.02 inches to about 0.35 inches. Thecover preferably has a thickness of about 0.02 inches to about 0.12inches, preferably about 0.1 inches or less. The cover may have athickness of about 0.1 inches or less, preferably about 0.07 inches orless. In one embodiment, the outer cover has a thickness from about 0.02inches to about 0.07 inches. In another embodiment, the cover thicknessis about 0.05 inches or less, preferably from about 0.02 inches to about0.05 inches. In yet another embodiment, the outer cover layer is betweenabout 0.02 inches to about 0.045 inches. In still another embodiment,the outer cover layer is about 0.025 to about 0.04 inches thick. In oneembodiment, the outer cover layer is about 0.03 inches thick.

The range of thicknesses for a mantle layer of a golf ball is largebecause of the vast possibilities when using a mantle layer, i.e., as anouter core layer, an inner cover layer, a wound layer, a moisture/vaporbarrier layer. When used in a golf ball of the invention, the mantlelayer, or inner cover layer, may have a thickness about 0.3 inches orless. In one embodiment, the thickness of the mantle layer is from about0.002 inches to about 0.1 inches, preferably about 0.01 inches orgreater. In one embodiment, the thickness of the mantle layer is about0.09 inches or less, preferably about 0.06 inches or less. In anotherembodiment, the mantle layer thickness is about 0.05 inches or less,more preferably about 0.01 inches to about 0.045 inches. In oneembodiment, the mantle layer, thickness is about 0.02 inches to about0.04 inches. In another embodiment, the mantle layer thickness is fromabout 0.025 inches to about 0.035 inches. In yet another embodiment, thethickness of the mantle layer is about 0.035 inches thick. In stillanother embodiment, the inner cover layer is from about 0.03 inches toabout 0.035 inches thick. Varying combinations of these ranges ofthickness for the mantle and outer cover layers may be used incombination with other embodiments described herein.

The ratio of the thickness of the mantle layer to the outer cover layeris preferably about 10 or less, preferably from about 3 or less. Inanother embodiment, the ratio of the thickness of the mantle layer tothe outer cover layer is about 1 or less.

The core and optional mantle layer(s) together form an inner ballpreferably having a diameter of about 1.48 inches or greater for a1.68-inch ball. In one embodiment, the inner ball of a 1.68-inch ballhas a diameter of about 1.52 inches or greater. In another embodiment,the inner ball of a 1.68-inch ball has a diameter of about 1.66 inchesor less. In yet another embodiment, the inner ball of a 1.68-inch ballhas a diameter of about 1.59 inches or less. In yet another embodiment,a 1.72-inch (or more) ball has an inner ball diameter of about 1.50inches or greater. In still another embodiment, the diameter of theinner ball for a 1.72-inch ball is about 1.70 inches or less.

Turning to the preferred method for making the ball of the presentinvention, the inner sphere is produced by forming the liquid centershell 20 to create a central cavity, and filling the cavity with thefluid center 18. A first cup is made by compression molding cup material31, preferably polybutadiene, between a first substantiallyhemispherical concave mold part 32 and a protrusive mold part 34. Theprotrusive mold part 34 has a first substantially hemisphericalprotrusion 35 that faces the first concave mold part 32. A second cup isthen made in the same manner.

Alternatively, as shown in FIG. 4, the two cups 30 are simultaneouslycompression molded about a single protrusive mold part 36 that has firstand second protrusions 35 and 37. First and second hemispherical molds32 and 33 are positioned opposite each other and protrusive mold part 36is placed between the hemispherical molds 32 and 33.

FIG. 5 shows two concave mold parts 32 and 33 after cups 30 have beenmolded. Each hemispherical cup 30 has a hemispherical cavity 44.Disposed around the cavities 44, the cups 30 have mating surfaces 46,which are substantially flat in this embodiment.

At this point in the process, the inner sphere 13 is placed in the cups30, and the two cups 30 are joined. Cups 30 are preferably kept in theirrespective hemispherical molds 32 and 33 during this step. The preferredmethod for joining the cups 30 is to place adhesive 42 between the cupsby applying the adhesive to one of the cups 30 as shown in FIG. 5. Thecups 30 are then brought together, squeezing the adhesive evenly acrossthe mating surfaces of the cups 30. The adhesive 42 then sets and bondsthe cups 30 to one another. The adhesive is also preferably applied suchthat it bonds the inner sphere 13 to the cups 30 by placing adhesive 42within the cavities. As with the adhesive 42 placed between cups, theadhesive 42 placed between the cups 30 and the inner sphere 13 is spreadevenly upon joining the cups 30 to one another. The hemisphericalcavities 44 of the joined cups together form a spherical cavity,occupied by the inner sphere 12.

Another method for joining the cups 30 is to compress them together atan elevated temperature to cause crosslinking between the elastomericcup material of each cup 30. In the embodiment shown in FIG. 4, this maybe achieved by removing protrusive mold part 36, and running thecompression mold through a second cycle, heating and compressing thecups 30 together.

FIG. 6 shows the inner sphere 13 and the cups 30 prior to their beingjoined. In this embodiment, the inner sphere is merely a sphere offrozen fluid 18 that placed between the cups 30, and around which thecups 30 are joined, preferably before the fluid 18 begins to melt.

Once the cups 30 are joined, the cover 11 is formed around the core 12,as seen in FIG. 8. FIG. 8 illustrates a step of compression molding twohalves 70 of a cover 11 around the core 12 in a dimpled mold 68. FIG. 9shows a step of injection molding the cover 11 around the core 12 in adimpled mold 60 with pins 62 that position the core 12 within thedimpled mold 60 and retract before the cover 11 cures completely.

The golf ball of FIG. 7 has been formed by adhesively joining the cups30. Adhesive 42 extends between the cups in the first mantle layer 22,and between the each cup 30 and the inner sphere 13. The adhesive 42preferably has an adhesive strength that is greater than the cohesivestrength of the elastomeric cup material. Thus, a ball can bemanufactured that is at least as strong as a ball in which the mantlelayer is made from a single piece of cup material, because the elastomerforming the cups 30 will fail under a lighter load than the adhesive 42.Ideally, the adhesive 42 is flexible in its cured state and has physicalproperties similar to those of the cup material employed.

A preferred adhesive for use with polybutadiene cups 30 is an epoxy,formed by blending low viscosity liquid resins, and formulated to beflexible in its cured state. A suitable epoxy is formed by mixing anapproximately 1:1 volume ratio of about 83 parts by weight of AB-82hardener into 100 parts by weight of Epoxy Resin #1028, both of whichare sold by RBC Industries, Inc. In its liquid state, the epoxy is idealfor use in metering, mixing, and dispensing equipment. This epoxy ispreferably cured at 77° F. for 18 to 24 hours, at 95° F. for 6 hours, at120° F. for 3 hours, or at 150° F. for 1 hour. The cured adhesive'sphysical properties resemble those of elastomeric urethane. It exhibitsan Izod impact strength of 5.50 ft. lbs./in. of notch, a tensilestrength at 25° C. of 2,200 psi, a compressive strength at 25° C. of6,000 psi, and a shore D hardness of 45. Preferably, the shore D of thecured adhesive is within 20 shore D of the hardness of the elastomericcup material.

Other preferred adhesives are those adhesives containing cyanoacrylate.

FIGS. 10 and 11 show alternative embodiments of cups 48 and 54. Insteadof having flat mating surfaces, cups 48 and 54 have nonplanar matingsurfaces 50 and 52, and 56 and 58. These surfaces 50 and 52, and 56 and58 each have a circular pattern of ridges that is preferably symmetricalabout the cavity 44 of each cup 48 and 54; the patterns shown areconcentric with the cups 48 and 54. In ball 53, surface 58 has a tonguethat engages a groove of surface 56. In the finished golf balls 47 and53, nonplanar surfaces 50 and 52 are arranged to mesh with each other,as are nonplanar surfaces 56 and 58. These nonplanar mating surfaces 50and 52 are preferably formed by molding the cups 48 or 54 withprotrusive mold parts that have nonplanar surfaces surrounding theirprotrusions, such as the protrusive mold part 36 with nonplanar surfaces64 and 66, as shown in FIG. 4.

The liquid center shell and mantle layers in the mantle portion 16 ofgolf balls with nonplanar mating surfaces retain more of the propertiesof the elastomers that form the cups, when the cups are forced in shearwith respect to each other, as compared to a golf ball with flat matingsurfaces. Nonplanar mating surfaces are thus advantageous when anadhesive is used that has an adhesive strength lower than the cohesivestrength of the elastomeric cup material. This is because the meshedportions of the cups 48 and 54 aid in resisting shearing forces betweenthe two cups 48 and 54.

While it is apparent that the illustrative embodiments of the inventionherein disclosed fulfills the objectives stated above, it will beappreciated that numerous modifications and other embodiments may bedevised by those skilled in the art, for example, a series ofprogressively larger diameter cups can be formed and joined by themethods disclosed. Therefore, it will be understood that the appendedclaims are intended to cover all such modifications and embodimentswhich come within the spirit and scope of the present invention.

The invention described and claimed herein is not to be limited in scopeby the specific embodiments herein disclosed, since these embodimentsare intended as illustrations of several aspects of the invention. Anyequivalent embodiments are intended to be within the scope of thisinvention. Indeed, various modifications of the invention in addition tothose shown and described herein will become apparent to those skilledin the art from the foregoing description. For example, the compositionsof the present invention may be used in a variety of golf equipment, forexample, golf shoes for sole applications, as well as in inserts forgolf putters. Such modifications are also intended to fall within thescope of the appended claims.

Various examples of golf ball cores according to the invention are setforth below.

EXAMPLES

The following examples are illustrative of the invention:

Example 1

A core according to the present invention was created having a liquidcenter, a liquid center shell surrounding the liquid center and a firstmantle layer surrounding the liquid center shell.

The liquid was a salt, water and corn syrup solution comprised of 40%salt, 30% water and 30% corn syrup. The liquid center had an outsidediameter of approximately 0.965 inches.

The liquid center shell was created from a thermoplastic elastomer. Theliquid center shell had an outside diameter of approximately 1.125inches.

The first mantle layer was created from crosslinked polybutadiene. Thefirst mantle layer had an outside diameter of approximately 1.51 inches.

The core weighed 38.9 g and had a PGA compression of less than 60.

Example 2

A core according to the present invention was created having a liquidcenter, liquid center shell surrounding the liquid center and a firstmantle layer surrounding the liquid center shell.

The liquid was a salt, water and corn syrup solution comprised of 40%salt, 30% water and 30% corn syrup. The liquid filled center had anoutside diameter of approximately 0.938 inches.

The liquid center shell was created from polypropylene. The liquidcenter shell had an outside diameter of approximately 1.0625 inches.

The first mantle layer was created from crosslinked polybutadiene. Thefirst mantle layer had an outside diameter of approximately 1.51 inches.

The core weighted 33.4 g and had a PGA compression of approximately 60.

Example 3

A core according to the present invention was created having a fluidcenter, a liquid center shell surrounding the fluid center and a firstmantle layer surrounding the liquid center shell.

The fluid was air. The fluid center had an outside diameter ofapproximately 0.938 inches.

The liquid center shell was created from polypropylene. The liquidcenter shell had an outside diameter of approximately 1.0625 inches.

The first mantle layer was created from crosslinked polybutadiene. Thefirst mantle layer had an outside diameter of approximately 1.51 inches.

The core weighed 26 g and had a PGA compression of approximately 87.

1. A golf ball having a diameter and being comprised of a core and acover, wherein the core is further comprised of a fluid mass at thecenter of the ball, a shell encompassing the fluid mass, and a first,solid, non-wound mantle layer surrounding the shell, wherein the firstmantle layer comprises a copolymer or terpolymer of ethylene and anα,β-unsaturated carboxylic acid, the acid being neutralized at least 80%by a salt of an organic acid or a suitable base of the organic acid, anda cation source, wherein the shell comprises a material selected fromthe group of polyolefin, polyethylene, polypropylene, polyurea, ionomer,acid copolymer, thermoplastic polyetherester, thermoplasticpolyetheramide, thermoplastic polyurethane, styrene butadiene copolymer,polycarbonate, polyester elastomer, polyamide elastomer, dynamicallyvulcanized thermoplastic elastomer, metallocene catalyzed polyolefiniccopolymers, fluoropolymer, functionalized fluoropolymer, andthermoplastic polyester, and wherein the liquid center shell has aninner diameter of about 0.25 to 1.5 inches and the mantle layer has anouter diameter of about 1.3 to 1.65 inches.
 2. The golf ball of claim 1,wherein the inner diameter is about 0.5 to 1.35 inches and the outerdiameter is about 1.45 to 1.62 inches.
 3. The golf ball of claim 1,wherein the shell comprises an inner surface having a texture.
 4. Thegolf ball of claim 1, wherein the cover comprises polyurethane,polyurea, or a polyurea/polyurethane hybrid.
 5. The golf ball of claim1, wherein the polymer composition acid being neutralized by contactingone or more acid polymer(s) with an organic acid or a metal salt of anorganic acid and a sufficient amount of a less hydrophilic cation sourcesuch that at least 90% of all acid functionalities present in thepolymer composition are neutralized.
 6. The golf ball of claim 5,wherein about 100% of all acid functionalities present in the polymercomposition are neutralized.
 7. The golf ball of claim 5, wherein theacid polymer is partially neutralized prior to contacting with the lesshydrophilic cation source.
 8. The golf ball of claim 1, wherein thecation source is selected from metal ions and compounds of potassium,cesium, calcium, barium, manganese, copper, zinc, and tin; silicone,silane, and silicate derivatives and complex ligands; and metal ions andcompounds of rare earth elements.
 9. The golf ball of claim 1, whereinthe first mantle layer has a thickness of about 0.04 to 0.35 inches. 10.The golf ball of claim 1, wherein the first mantle layer furthercomprises polybutadiene.
 11. The golf ball of claim 1, wherein the fluidmass is a gas, liquid, gel, paste or a combination thereof.
 12. The golfball of claim 1, wherein the specific gravity of the fluid mass is about1.3 to 1.55.
 13. The golf ball of claim 1, wherein the viscosity of thefluid mass is about 100 to 1500 cps.
 14. The golf ball of claim 1,wherein the golf ball has a rate of spin decay of at least 10% of theinitial spin rate over the entire ball flight.
 15. The golf ball ofclaim 14, wherein the golf ball has a rate of spin decay of at least 15%of the initial spin rate over the entire ball flight.
 16. The golf ballof claim 1, wherein the cover comprises an inner cover layer and a thinouter cover layer, wherein the outer cover layer comprises a thermosetmaterial formed from a castable, reactive liquid and the inner coverlayer comprises a high flexural modulus material.
 17. The golf ball ofclaim 1, wherein the core has a compression of 87 or less.